Re: [PATCH v2 2/3] selftests: kvm: s390: Add uc_skey VM test case

["Christoph Schlameuss" <schlameuss@linux.ibm.com>]

On Thu Sep 12, 2024 at 10:15 AM CEST, Claudio Imbrenda wrote:
> On Mon,  2 Sep 2024 13:50:01 +0200
> Christoph Schlameuss <schlameuss@linux.ibm.com> wrote:
>
> > Add a test case manipulating s390 storage keys from within the ucontrol
> > VM.
> > 
> > Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
> > ---
> >  .../selftests/kvm/s390x/ucontrol_test.c       | 89 ++++++++++++++++++-
> >  1 file changed, 88 insertions(+), 1 deletion(-)

[...]

> > +TEST_F(uc_kvm, uc_skey)
> > +{
> > +	u64 test_vaddr = VM_MEM_SIZE - (SZ_1M / 2);
> > +	struct kvm_sync_regs *sync_regs = &self->run->s.regs;
> > +	struct kvm_run *run = self->run;
> > +	u8 skeyvalue = 0x34;
> > +
> > +	/* copy test_skey_asm to code_hva / code_gpa */
> > +	TH_LOG("copy code %p to vm mapped memory %p / %p",
> > +	       &test_skey_asm, (void *)self->code_hva, (void *)self->code_gpa);
> > +	memcpy((void *)self->code_hva, &test_skey_asm, PAGE_SIZE);
> > +
> > +	/* set register content for test_skey_asm to access not mapped memory */
> > +	sync_regs->gprs[1] = skeyvalue;
> > +	sync_regs->gprs[5] = self->base_gpa;
> > +	sync_regs->gprs[6] = test_vaddr;
> > +	run->kvm_dirty_regs |= KVM_SYNC_GPRS;
> > +
> > +	/* DAT disabled + 64 bit mode */
> > +	run->psw_mask = 0x0000000180000000ULL;
> > +	run->psw_addr = self->code_gpa;
> > +
> > +	ASSERT_EQ(0, uc_run_once(self));
> > +	ASSERT_EQ(false, uc_handle_exit(self));
>
> this should be true, since KSS will be triggered
>

Good find.
Yes, as this is the assertion does actually fail here.
Will fix that in the next version.

> > +	ASSERT_EQ(1, sync_regs->gprs[0]);
> > +
> > +	/* ISKE */
> > +	ASSERT_EQ(0, uc_run_once(self));
> > +	ASSERT_EQ(false, uc_handle_exit(self));
> > +	ASSERT_EQ(2, sync_regs->gprs[0]);
> > +	/* assert initial skey (ACC = 0, R & C = 1) */
> > +	ASSERT_EQ(0x06, sync_regs->gprs[1]);
> > +	uc_assert_diag44(self);

[...]